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<table width="100%" summary="page for skulls"><tr><td>skulls</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2> Egyptian Skulls </h2>

<h3>Description</h3>

<p>Measurements made on Egyptian skulls from five epochs.
</p>


<h3>Usage</h3>

<pre>data("skulls")</pre>


<h3>Format</h3>

<p>A data frame with 150 observations on the following 5 variables.
</p>

<dl>
<dt><code>epoch</code></dt><dd><p>the epoch the skull as assigned to, 
a factor with levels <code>c4000BC</code> <code>c3300BC</code>,
<code>c1850BC</code>,  <code>c200BC</code>, and  <code>cAD150</code>,
where the years are only given approximately, of
course.</p>
</dd>
<dt><code>mb</code></dt><dd><p>maximum breaths of the skull.</p>
</dd>
<dt><code>bh</code></dt><dd><p>basibregmatic heights of the skull.</p>
</dd>
<dt><code>bl</code></dt><dd><p>basialiveolar length of the skull.</p>
</dd>
<dt><code>nh</code></dt><dd><p>nasal heights of the skull.</p>
</dd>
</dl>



<h3>Details</h3>

<p>The question is whether the measurements change over time.
Non-constant measurements of the skulls over time would indicate
interbreeding with immigrant populations.
</p>


<h3>Source</h3>

<p>D. J. Hand, F. Daly, A. D. Lunn, K. J. McConway and E. Ostrowski (1994).
<em>A Handbook of Small Datasets</em>, Chapman and Hall/CRC, London.
</p>


<h3>Examples</h3>

<pre>

  data("skulls", package = "HSAUR")
  means &lt;- tapply(1:nrow(skulls), skulls$epoch, function(i)
               apply(skulls[i,colnames(skulls)[-1]], 2, mean))
  means &lt;- matrix(unlist(means), nrow = length(means), byrow = TRUE)
  colnames(means) &lt;- colnames(skulls)[-1]
  rownames(means) &lt;- levels(skulls$epoch)
  pairs(means,
      panel = function(x, y) {
          text(x, y, levels(skulls$epoch))
      })

</pre>


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